XML 60 R47.htm IDEA: XBRL DOCUMENT
v3.4.0.3

Fair Value - Recurring Fair Value Measures (Details) - USD ($) $ in Millions | 3 Months Ended | 12 Months Ended
--- | --- | ---
Mar. 31, 2016 | Dec. 31, 2015
Investments [Abstract] |  |  |  |  |
Cash Equivalents |  | $ 2.5 |  | $ 2.0 |
Liabilities [Abstract] |  |  |  |  |
U.S. Water Services Contingent Consideration | [1] | 36.7 |  | 36.6 |
Recurring Fair Value Measurements [Member] |  |  |  |  |
Investments [Abstract] |  |  |  |  |
Available-for-sale – Equity Securities |  | 7.0 | [2] | 7.6 | [3]
Available-for-sale – Corporate Debt Securities |  | 10.4 | [2] | 10.9 | [3]
Cash Equivalents |  | 2.5 | [2] | 2.0 | [3]
Total Fair Value of Assets |  | 19.9 |  | 20.5 |
Liabilities [Abstract] |  |  |  |  |
Deferred Compensation |  | 14.9 | [4] | 16.1 | [5]
U.S. Water Services Contingent Consideration |  | 36.7 | [4] | 36.6 | [5]
Total Fair Value of Liabilities |  | 51.6 |  | 52.7 |
Total Net Fair Value of Assets (Liabilities) |  | (31.7) |  | (32.2) |
Fair Value Hierarchy Transfers, All Levels |  | 0.0 |  | 0.0 |
Recurring Fair Value Measurements [Member] | Level 1 [Member] |  |  |  |  |
Investments [Abstract] |  |  |  |  |
Available-for-sale – Equity Securities |  | 7.0 | [2] | 7.6 | [3]
Available-for-sale – Corporate Debt Securities |  | 0.0 | [2] | 0.0 | [3]
Cash Equivalents |  | 2.5 | [2] | 2.0 | [3]
Total Fair Value of Assets |  | 9.5 |  | 9.6 |
Liabilities [Abstract] |  |  |  |  |
Deferred Compensation |  | 0.0 | [4] | 0.0 | [5]
U.S. Water Services Contingent Consideration |  | 0.0 | [4] | 0.0 | [5]
Total Fair Value of Liabilities |  | 0.0 |  | 0.0 |
Total Net Fair Value of Assets (Liabilities) |  | 9.5 |  | 9.6 |
Recurring Fair Value Measurements [Member] | Level 2 [Member] |  |  |  |  |
Investments [Abstract] |  |  |  |  |
Available-for-sale – Equity Securities |  | 0.0 | [2] | 0.0 | [3]
Available-for-sale – Corporate Debt Securities |  | 10.4 | [2] | 10.9 | [3]
Cash Equivalents |  | 0.0 | [2] | 0.0 | [3]
Total Fair Value of Assets |  | 10.4 |  | 10.9 |
Liabilities [Abstract] |  |  |  |  |
Deferred Compensation |  | 14.9 | [4] | 16.1 | [5]
U.S. Water Services Contingent Consideration |  | 0.0 | [4] | 0.0 | [5]
Total Fair Value of Liabilities |  | 14.9 |  | 16.1 |
Total Net Fair Value of Assets (Liabilities) |  | (4.5) |  | (5.2) |
Recurring Fair Value Measurements [Member] | Level 3 [Member] |  |  |  |  |
Investments [Abstract] |  |  |  |  |
Available-for-sale – Equity Securities |  | 0.0 | [2] | 0.0 | [3]
Available-for-sale – Corporate Debt Securities |  | 0.0 | [2] | 0.0 | [3]
Cash Equivalents |  | 0.0 | [2] | 0.0 | [3]
Total Fair Value of Assets |  | 0.0 |  | 0.0 |
Liabilities [Abstract] |  |  |  |  |
Deferred Compensation |  | 0.0 | [4] | 0.0 | [5]
U.S. Water Services Contingent Consideration |  | 36.7 | [4] | 36.6 | [5]
Total Fair Value of Liabilities |  | 36.7 |  | 36.6 |
Total Net Fair Value of Assets (Liabilities) |  | $ (36.7) |  | $ (36.6) |
[1] | Contingent Consideration relates to the estimated fair value of the earnings-based payment resulting from the U.S. Water Services acquisition. (See Note 3. Acquisitions and Note 5. Fair Value.)
[2] | Included in Other Investments on the Consolidated Balance Sheet.
[3] | Included in Other Investments on the Consolidated Balance Sheet.
[4] | Included in Other Non-Current Liabilities on the Consolidated Balance Sheet.
[5] | Included in Other Non-Current Liabilities on the Consolidated Balance Sheet.

X
- Definition This element represents the portion of the balance sheet assertion, Deferred Compensation, valued at fair value by the entity. + References No definition available. + Details
Name: | ale_DeferredCompensationFairValueDisclosure
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The amount of transfers in and out of levels 1, 2, and 3 of the fair value hierarchy during the period. + References No definition available. + Details
Name: | ale_FairValueTransfersBetweenLevelsAllLevels
Namespace Prefix: | ale_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value on a recurring basis by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. + References No definition available. + Details
Name: | us-gaap_AssetsFairValueDisclosureRecurring
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Total of debt securities categorized neither as held-to-maturity nor trading which are intended be sold or mature more than one year from the balance sheet date or operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26626-111562 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecuritiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Equity securities categorized neither as held-to-maturity nor trading which are intended be sold more than one year from the balance sheet date or operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26626-111562 + Details
Name: | us-gaap_AvailableForSaleSecuritiesEquitySecuritiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of liability recognized arising from contingent consideration in a business combination, expected to be settled beyond one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 25 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6911189&loc=d3e6408-128476 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 35 -Paragraph 1 -Subparagraph b -URI http://asc.fasb.org/extlink&oid=6911338&loc=d3e6819-128478 + Details
Name: | us-gaap_BusinessCombinationContingentConsiderationLiabilityNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of asset after deduction of liability. + References No definition available. + Details
Name: | us-gaap_FairValueNetAssetLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_LiabilitiesFairValueDisclosureAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity. + References No definition available. + Details
Name: | us-gaap_LiabilitiesFairValueDisclosureRecurring
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Other long-term assets not otherwise listed in the existing taxonomy that are pledged or subject to withdrawal restrictions. + References No definition available. + Details
Name: | us-gaap_OtherRestrictedAssetsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |